Compact allen key organizer for 6 keys, sizes: 1.5, 2, 2.5, 3, 4 and 5 mm.
Features a slot at the back to glue a magnet in.

Print instructions

For optimal fit, print in 0.1mm layer height (with the back face down)

Or maybe you can print with a coarser setting if you orient the object standing upright. Let me know how it works if you try it that way.